[Arm-netbook] laptop casework, jz4775 cpu card, fosdem 2016

[Luke Kenneth Casson Leighton]

hi folks,

right. i've moved on to re-printing the 3d casework of the laptop,
most of that will be in higher-temperature ABS. i'm about 50% the way
through that, so another 2-3 days and i'll have an assembled
prototype. some bamboo 1.5mm plywood panels are arriving from a U.S.
supplier (the only one in the world that sells online 1.5mm bamboo!)
are arriving shortly.

the jz4775 cpu card, it turns out that digikey sent the wrong PMIC.
bizarre story: the ACT8600-QJ162-T became popular in the past few
months because of a smartwatch that was developed in china using the
ingenic jz4775 reference design. so the formerly popular
ACT8600-QJ601-T suddenly became UNpopular, leaving the world's last
remaining supplier as being digikey. so, that's a china-made PMIC,
which got shipped to the U.S. (customs-charge), got shipped back to
china (customs-charges), then provided by the agent to the factory,
then the factory put it on the PCB, then they sent that to me (customs
charges)... and then it turns out to be the wrong f*****g IC.

naturally it took a whole lot of shouting at digikey to get them to do
a full audit of the stock of ACT8600-QJ601-T PMICs, but i've placed an
order for replacements - to be sent directly to me - and will be
putting those on when they arrive. also, only 1 out of the 6 PCBs
happened to _not_ have solder-bridges under the DDR3 RAM ICs, so i've
ordered some replacement DDR3 RAM and will be having a go at putting
on 78-pin BGAs with the IRDA solder station. it'll be fun to try.
ok.... correction: it'll be fun to succeed.

also even though it's short notice i'm looking to go to fosdem 2016
because i happen to be in den haag at the moment, it's only a train
ride to brussels after all. i'll be bringing along the completed
laptop prototype if anybody would like to see it.

l.


---
crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68

_______________________________________________
arm-netbook mailing list arm-***@lists.phcomp.co.uk
http://lists.phcomp.co.uk/mailman/listinfo/arm-netbook
Send large attachments to arm-***@files.phcomp

[Paul Boddie]

Post by Luke Kenneth Casson Leighton
naturally it took a whole lot of shouting at digikey to get them to do
a full audit of the stock of ACT8600-QJ601-T PMICs, but i've placed an
order for replacements - to be sent directly to me - and will be
putting those on when they arrive. also, only 1 out of the 6 PCBs
happened to _not_ have solder-bridges under the DDR3 RAM ICs, so i've
ordered some replacement DDR3 RAM and will be having a go at putting
on 78-pin BGAs with the IRDA solder station. it'll be fun to try.
ok.... correction: it'll be fun to succeed.

So, was it Digikey that mixed up the parts or the factory that put the wrong
IC on the board?

As for the RAM, I guess that it made for the "bring up" process, as described
in that bare-metal Ingenic work, to be slightly more exciting than it should
have been. When you're probably only somewhat confident that the code will do
the trick, I guess it's frustrating to have defective hardware involved as
well.

Anyway, good luck with the printing and soldering!

Paul

_______________________________________________
arm-netbook mailing list arm-***@lists.phcomp.co.uk
http://lists.phcomp.co.uk/mailman/listinfo/arm-netbook
Send l

[Luke Kenneth Casson Leighton]

---
crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68

Post by Paul Boddie

Post by Luke Kenneth Casson Leighton
naturally it took a whole lot of shouting at digikey to get them to do
a full audit of the stock of ACT8600-QJ601-T PMICs, but i've placed an
order for replacements - to be sent directly to me - and will be
putting those on when they arrive. also, only 1 out of the 6 PCBs
happened to _not_ have solder-bridges under the DDR3 RAM ICs, so i've
ordered some replacement DDR3 RAM and will be having a go at putting
on 78-pin BGAs with the IRDA solder station. it'll be fun to try.
ok.... correction: it'll be fun to succeed.

So, was it Digikey that mixed up the parts or the factory that put the wrong
IC on the board?

digikey. they just sent - a second time - the exact same wrong part,
after i specifically advised them on the process by which they could
verify what the part was.

Post by Paul Boddie
As for the RAM, I guess that it made for the "bring up" process, as described
in that bare-metal Ingenic work, to be slightly more exciting than it should
have been.

yyyyeah.... but luckily there's debug information printed in the
u-boot SPL section that allowed a diagnosis.

Post by Paul Boddie
When you're probably only somewhat confident that the code will do
the trick, I guess it's frustrating to have defective hardware involved as
well.

it's why the "reduce it to one and only one change" is so absolutely critical.

Post by Paul Boddie
Anyway, good luck with the printing and soldering!

thanks... :)

l.

_______________________________________________
arm-netbook mailing list arm-***@lists.phcomp.co.uk
http://lists.phcomp.co.uk/mailman/listinfo/arm-netbook
Send large attachments to